1. Field of the Invention
This invention relates to antibodies specific for proteins differentially expressed in normal and tumor or precancerous cells and tissues and methods of use thereof. The invention more specifically relates to antibodies that are immunologically specific for a particular human protein, ARL-1 (also referred to as AKR1B10), a species of protein in the aldo-keto reductase (AKR) superfamily. The invention particularly relates to polyclonal antisera, monoclonal antibodies and fragments and derivatives thereof that are immunologically specific for ARL-1 differentially expressed in normal and tumor or precancerous cells and tissues. Methods for making and using said antibodies are also provided. In specific embodiments, the invention provides methods for detecting ARL-1 using said antibodies for detecting cancer and precancerous lesions, cancer recurrence and cancer metastasis.
2. Summary of the Related Art
Cancer remains one of the leading causes of death in the United States, with colon cancer representing the second leading cause of cancer death, and breast cancer being the leading cause of cancer death in women (Nyska et al., 2001, Arch Toxicol. 75: 618-624). It has long been recognized that development of cancer, particularly cancers that occur in later life such as colon cancer, are in part the result of lifelong exposure to environmental carcinogens. Surprisingly, many of these carcinogens are contained in or produced from foods and other natural products. See, Ames, 1983, Science 221: 1256-1264
For example, electrophilic carbonyls are constantly produced during metabolism of carbohydrate and lipid (Davydov et al., 2004, Exp Gerontol. 39: 11-16; De Bont & van Larebeke, 2004, Mutagenesis 19: 169-185; Choudhary et al., 2005, Toxicol Appl Pharmacol 204: 122-134, 2005). Carbonyls also widely exist in air, water, and various foodstuffs and beverages (Bowmer & Higgins, 1976, Arch Environ Contam Toxicol. 5: 87-96; Schuler & Eder, 2000, Arch Toxicol. 74: 404-414; Seaman et al., 2006, Anal Chem. 78: 2405-2412). Human exposure to carbonyls occurs in consumption of fruits, vegetables, fish, meat, and alcoholic beverages, such as wine and whisky (Bowmer & Higgins, 1976, Id; Uchida et al., 1998, Proc Natl Acad Sci USA 95: 4882-4887). Indeed, carcinogenic methylglyoxal is a constituent of daily consumed coffee, whereas carcinogenic crotonaldehyde is widely present in fruit (5.4-78 μg/kg), vegetables (1.4-100 μg/kg), fish (71.4-1000 μg/kg), meat (10-270 μg/kg), and alcoholic beverages, such as wine (300-700 μg/L) and whisky (30-210 μg/L) (Schuler et al., 2000, Arch Toxicol. 74: 404-414.).
Because of their reactivity, carbonyls can interact with free amino and sulfhydryl groups of proteins, peptides and amino acids, forming covalently modified adducts (Davydov et al., 2004, Id.; Vasiliou et al., 2000, Chem Biol Interact. 129: 1-19; Hashimoto et al., 2003, J Biol. Chem. 278: 5044-5051; Okada et al., 1999, J Biol. Chem. 274: 23787-23793; Uchida et al., 1992, Proc Natl Acad Sci USA, 89: 5611-5615). These non-specific, covalent modifications may cause protein dysfunction, resistance to intracellular proteolysis, or depolymerization. Protein adducts may also act as secondary messengers, autoantigens, or inhibitors of proteosomes, causing cellular damage and/or autoimmune disorders.
Electrophilic carbonyls can also react with nucleic acids (DNA), forming covalently modified DNA adducts. DNA adducts can block DNA semiconservative replication performed by DNA polymerase, arrest transcription driven by RNA polymerase, and cause DNA mutations and breaks (De Bont & van Larebeke, 2004, Id.; Yang et al., 2002, Biochemistry 41: 13826-13832; Hou et al., 1995, Environ Mol Mutagen 26: 286-291; Nagy et al., 2005, Carcinogenesis 26: 1821-1828; Cline et al., 2004, Proc Natl Acad Sci USA 101: 7275-7280, 2004). Documented evidence has indicated the pathogenic effect of carbonyl-derived DNA modifications, resulting in mutagenesis, carcinogenesis, and other age-related diseases (Davydov et al., 2004, Id.; Yang et al., 2002, Biochemistry 41: 13826-13832; Nagy et al., 2005, Carcinogenesis 26: 1821-1828; Ames, 1983, Id.).
Consequently, electrophilic dietary carbonyls are important pathogens of gastrointestinal (GI) diseases, including neoplasms (Homann et al., 2000, Int J Cancer 86: 169-173; Nyska et al., 2001, Id.; Korenaga et al., 2002, J Surg Res 102: 144-149; Schaeferhenrich et al., 2003, Mutat Res. 526: 19-32). Via food consumption, GI cells are repeatedly exposed to various reactive carbonyls (Ames, 1983, Id.; Fujioka & Shibamoto, 2004, Lipids 39: 481-486, 2004). This long-term and cumulative carbonyl exposure, even though minimal in each instance, may eventually cause carcinogenic changes of GI cells after cumulative exposure thereto. Indeed, exposure of F344 rats to 2,4-hexadienal induced stomach hyperplasia, squamous papilloma, and carcinoma, and high levels of malondialdehyde (MDA) in colonic mucosa has been pathogenically related to neoplastic lesions in ulcerative colitis (Korenaga et al., 2002, Id.; Nyska et al., 2001, Id.). In addition, local accumulation of acetaldehyde, microbially produced after alcohol consumption, has been considered a carcinogenic factor for colon and gastric cancers (Homann et al., 2000, Id.; Salaspuro, 2003, Best Pract Res Clin Gastroenterol. 17: 679-694).
Nevertheless, little is known of the GI-specific protective mechanisms against carcinogenic lesions induced by dietary carbonyls. Aldehyde dehydrogenase and glutathione-S-transferase (GST) are important enzymes in elimination of intracellular carbonyls by catalyzing carbonyl oxidation to carbonic acids or conjugation with glutathione, but no evidence demonstrates their GI-specificity (Vasiliou et al., 2000, Id.; Sladek, 2003, J Biochem Mol. Toxicol. 17: 7-23; Coles & Kadlubar, 2003, Biofactors 17: 115-130; Sharma et al., 2004, Antioxid Redox Signal. 6: 289-300, 2004).
There is therefore a need in this art to identify endogenous protective mechanisms and proteins involved in such mechanisms. There is further a need in this art to identify whether differential expression of proteins involved in protecting gastrointestinal cells and tissues from the mutagenic and carcinogenic effects of food-related reactive carbonyls provides a marker for cells and tissues at risk for neoplastic transformation and tumor formation, or identifies cells having resistance to anticancer chemotherapeutic drugs, or provides a target for therapeutic and prevention interventions in cancer or precancerous states.
There is also a need in the art to understand the roles of proteins involved in these endogenous protective mechanisms in the tumorigenesis process in other tissues, such as liver, lung, prostate and breast, and for evaluating the clinical relevance of these proteins as markers for cancer in these tissues. Currently, mammography is the only routinely used method for breast cancer screening, with a reported 67.8% sensitivity and 75% specificity for detecting DCIS (ductal carcinoma in situ). However, mammography is costly and the interpretation of results are affected by multiple factors, such as density of breast tissue, experience of radiologists, and volume of tumor cells in a specific location (Berg et al., 2004, Radiology 233: 830-849; Burnside et al., 2005, AJR Am J. Roentgeno. 185: 790-796). Further, for women undergoing hormone replacement therapy, the sensitivity of mammography for detecting breast cancer can be as low as 25% (Kolb et al., 2002, Radiology 225: 165-175).
Currently, estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are representatives of therapeutic targets for breast cancer, and targeted therapies of theses markers have significantly improved clinical outcomes of breast cancer (Sehdev et al., 2009, Curr Oncol 16: S14-23; Dowsett et al., 2006, Ann Oncol 17: 818-826; Slamon et al., 1987, Science 235: 177-182; and Dowsett et al., 2008, J Clin Oncol 26: 1059-1065). These targeted therapies, however, cannot benefit patients who have triple negative breast cancer (Tan et al., 2008, Cancer 14: 343-351). Moreover, the use of these receptor markers for early detection and prognostic prediction is limited (Esteva et al., 2004, Breast Cancer Res 6: 109-118). Other biomarkers currently used in breast cancer detection include cancer antigen (CA) 15-3, carcinoembryonic antigen (CEA), ki-67, toposiomerase IIa, and oncotype DX (Duffy et al., 2006, Clin Chem 52: 345-351; Levenson et al., 2007, Biochim Biophys Acta 1770: 847-856; Urruticoechea et al., 2005, J Clin Oncol 23: 7212-7220; Pritchard et al., 2008, J Clin Oncol 26: 736-744; Mariani et al., 2009, Biomarkers 14: 130-136; and Conlin et al., 2007, Mol Diagn Ther 11: 355-360). However, these markers lack sensitivity for early detection and disease-related specificity, and have not been demonstrated as having valid clinical relevance. Therefore, a better marker for detecting cancers, breast cancer in particular, with high sensitivity and specificity is needed.